91 resultados para DENDRITIC BRANCHING FEATURES


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Fibers growing, branching, and bundling are essential for the development of crystalline fiber networks of molecular gels. In this work, for two typical crystalline fiber networks, i.e. the network of spherulitic domains and the interconnected fibers network, related kinetic information is obtained using dynamic rheological measurements and analysis in terms of the Avrami theory. In combination with microstructure characterizations, we establish the correlation of the Avrami derived kinetic parameter not only with the nucleation nature and growth dimensionality of fibers and branches, but also with the fiber bundles induced by fiber-fiber interactions. Our study highlights the advantage of simple dynamic rheological measurements over other spectroscopic methods used in previous studies for providing more kinetic information on fiber-fiber interactions, enabling the Avrami analyses to extract distinct kinetic features not only for fibers growing and branching, but also for bundling in the creation of strong interconnected fibers networks. This work may be helpful for the implementation of precise kinetic control of crystalline fiber network formations for achieving desirable microstructures and rheological properties for advanced applications of gel materials. This journal is © the Partner Organisations 2014.

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The physicochemical attributes of 66 coastal dune lakes (lagoons) on islands of Bass Strait have been investigated. The full data set is available electronically. Here, selected environmental variables with known ecological significance are presented and, by reference to known sites of floristic richness in Tasmania, the lagoons most likely to harbour endemic freshwater algae are identified, as biogeographical stepping stones between the Tasmanian and mainland Australian microfloras.

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The mean total length (LT), mass and age of ready to migrate female silver shortfin eels Anguilla australis from the Hopkins River estuary and the mouth of the Merri River in south-eastern Australia, were 83·2 ± 1·2 cm, 1051 ± 51 g, and 17·2 ± 1·79 years, respectively. The eye index (IE) of the silver shortfin eels was < 5·2 (mean 7·64 ± 0·29) and differed significantly from that of the yellow shortfin eels collected from two other sites. The IE increased with LT (mm) and was related by log IE= 2·656 log LT6·925. The per cent moisture, protein and ash content of the liver of silver shortfin eels was significantly lower than in yellow shortfin eels, but lipid content was significantly higher in the former (35·5 ± 2·0%). The mean mass μg mg lipid ‾) of saturates (230·4 ± 2·6 v. 181·7 ±2·6), monoenes (367·4 ± 6·3 v. 290·8 ± 8·9) and PUFA (177·3 ± 5·3 v. 159·7 ± 4·6) in muscle was significantly higher, and the great majority of individual fatty acids was found also in higher quantities in silver shortfin eels. In the liver, the PUFA found in the highest quantity was 22:6n-3, except in shortfin eels from Hopkins River estuary, and the amount of 18:2n-6 in the liver of silver shortfin eels was significantly higher than that in yellow shortfin eels but the reverse was true of 20:4n-6. In both muscle and liver tissues the saturate 16:0 and the monoene 18:ln-9 collectively accounted for >50% of all the fatty acids in the lipid.

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The microstructures of hot- and cold-rolled Mg-3Al-1Zn (AZ31) are examined using scanning electron and optical microscopy. It is shown that the microstructures following multipass hot rolling and annealing are more uniform than those formed by heavy single pass rolling and annealing. The importance of twins in producing intragranular recrystallization is evident, although the most dominant nucleation site is grain boundaries. The cold-rolled structure after a rolling reduction of 15 pct is dominated by the presence of deformation twins. Twin trace analysis suggests that approximately two thirds of the twins are a form of “c-axis compression” twin. A number of “c-axis tension” twins were also observed and additional in-situ scanning electron microscopy experiments were performed to confirm earlier observations that suggest these twins can form after deformation, during unloading.

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This paper describes an approach for electronic feature extraction from fingerprint images for identification purposes. Statistical analysis of the features extracted from the fingerprint provides the advantage of real-time analysis of the fingerprint information, providing a method to remove unwanted information prior to the matching stage required in electronic fingerprint verification. This method can also detect of noise within the fingerprint image and location of critical data in the fingerprint. In order to demonstrate the effectiveness of this work, experiments have been developed and conducted with the results and analysis provided at the end of this paper for discussion.

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This study investigated the clinical features of patellar tendinopathy (PT), with focus on individuals with unilateral and bilateral PT. A cross-sectional study design was employed to compare individuals with unilateral (n = 14) or bilateral (n = 13) PT and those without PT (control, n = 31). Features assessed included thigh strength (normalized peak knee extensor torque) and flexibility (sit-and-reach and active knee extension), calf endurance (heel-rise test), ankle flexibility (dorsiflexion), alignment measures (arch height and leg length difference), and functional measures (hop for distance and 6 m hop test). Groups were matched for age and height; however, unilateral and bilateral PT had greater mass with a higher body mass index (BMI) than control. Also, bilateral PT performed more sport hours per week than both unilateral PT and control. Unilateral PT had less thigh strength than control and bilateral PT, whereas bilateral PT had more thigh flexibility than control and unilateral PT. Both unilateral and bilateral PT had altered alignment measures compared to control. Features that predicted symptoms in PT were lower thigh flexibility and strength, whereas those that predicted function were higher thigh strength and lower ankle flexibility.  These findings indicate that unilateral and bilateral PT represent distinct entities, and that thigh strength appears particularly important in PT as it predicted both symptoms and function in PT.

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In the last decade, the efforts of spoken language processing have achieved significant advances, however, the work with emotional recognition has not progressed so far, and can only achieve 50% to 60% in accuracy. This is because a majority of researchers in this field have focused on the synthesis of emotional speech rather than focusing on automating human emotion recognition. Many research groups have focused on how to improve the performance of the classifier they used for emotion recognition, and few work has been done on data pre-processing, such as the extraction and selection of a set of specifying acoustic features instead of using all the possible ones they had in hand. To work with well-selected acoustic features does not mean to delay the whole job, but this will save much time and resources by removing the irrelative information and reducing the high-dimension data calculation. In this paper, we developed an automatic feature selector based on a RF2TREE algorithm and the traditional C4.5 algorithm. RF2TREE applied here helped us to solve the problems that did not have enough data examples. The ensemble learning technique was applied to enlarge the original data set by building a bagged random forest to generate many virtual examples, and then the new data set was used to train a single decision tree, which selects the most efficient features to represent the speech signals for the emotion recognition. Finally, the output of the selector was a set of specifying acoustic features, produced by RF2TREE and a single decision tree.

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Although CD8+ T cells do not contribute to protection against the blood stage of Plasmodium infection, there is mounting evidence that they are principal mediators of murine experimental cerebral malaria (ECM). At present, there is no direct evidence that the CD8+ T cells mediating ECM are parasite-specific or, for that matter, whether parasite-specific CD8+ T cells are generated in response to blood-stage infection. To resolve this and to define the cellular requirements for such priming, we generated transgenic P. berghei parasites expressing model T cell epitopes. This approach was necessary as MHC class I-restricted antigens to blood-stage infection have not been defined. Here, we show that blood-stage infection leads to parasite-specific CD8+ and CD4+ T cell responses. Furthermore, we show that P. berghei-expressed antigens are cross-presented by the CD8α+ subset of dendritic cells (DC), and that this induces pathogen-specific cytotoxic T lymphocytes (CTL) capable of lysing cells presenting antigens expressed by blood-stage parasites. Finally, using three different experimental approaches, we provide evidence that CTL specific for parasite-expressed antigens contribute to ECM.

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Objective : To examine associations between features of public open spaces, and children's physical activity.
Participants : 163 children aged 8–9 years and 334 adolescents aged 13–15 years from Melbourne, Australia participated in 2004.
Methods : A Geographic Information System was used to identify all public open spaces (POS) within 800 m of participants' homes and their closest POS. The features of all POS identified were audited in 2004/5. Accelerometers measured moderate-to-vigorous physical activity (MVPA) after school and on weekends. Linear regression analyses examined associations between features of the closest POS and participants' MVPA.
Results : Most participants had a POS within 800 m of their home. The presence of playgrounds was positively associated with younger boys' weekend MVPA (B = 24.9 min/day; p ≤ 0.05), and lighting along paths was inversely associated with weekend MVPA (B = − 54.9 min/day; p ≤ 0.05). The number of recreational facilities was inversely associated with younger girls' MVPA after school (B = − 2.6 min/day; p ≤ 0.05) and on the weekend (B = − 8.7 min/day; p ≤ 0.05). The presence of trees providing shade (5.8 min/day, p ≤ 0.01) and signage regarding dogs (B = 6.8 min/day, p ≤ 0.05) were positively associated with adolescent girls' MVPA after school.
Conclusion : Certain features of POS were associated with participants' MVPA, although mixed associations were evident. Further research is required to clarify these complex relationships.

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This study examined the relations between neighbourhood socio-economic status and features of public open spaces (POS) hypothesised to influence children's physical activity. Data were from the first follow-up of the Children Living in Active Neighbourhoods (CLAN) Study, which involved 540 families of 5–6 and 10–12-year-old children in Melbourne, Australia. The Socio-Economic Index for Areas Index (SEIFA) of Relative Socio-economic Advantage/Disadvantage was used to assign a socioeconomic index score to each child's neighbourhood, based on postcode. Participant addresses were geocoded using a Geographic Information System. The Open Space 2002 spatial data set was used to identify all POS within an 800 m radius of each participant's home. The features of each of these POS (1497) were audited. Variability of POS features was examined across quintiles of neighbourhood SEIFA. Compared with POS in lower socioeconomic neighbourhoods, POS in the highest socioeconomic neighbourhoods had more amenities (e.g. picnic tables and drink fountains) and were more likely to have trees that provided shade, a water feature (e.g. pond, creek), walking and cycling paths, lighting, signage regarding dog access and signage restricting other activities. There were no differences across neighbourhoods in the number of playgrounds or the number of recreation facilities (e.g. number of sports catered for on courts and ovals, the presence of other facilities such as athletics tracks, skateboarding facility and swimming pool). This study suggests that POS in high socioeconomic neighbourhoods possess more features that are likely to promote physical activity amongst children.